Papermker&#39;s felt



May 16, 1961 H. M. HELLAND 2,983,986

PAPERMAKER S FELT Filed May 6, 1959 FIG.4

`\\\\ INVENTOR:

HO'WARDMHELLAND Patented May 16, 1961 ,Unite States Patent @me 2,983,986PAPERMAKERS FELT Filed May 6, I1959,' ser. N. 811,421 1 '7 cli'msgicl.asi-17s) p This invention relatesto a structurally improvedpapermakersfelt, such as for `use Iforvexample in themanufacture'ofpaper, paper board, pulp, and similar items suclfasf` for,example asbestos shingles, Transite pipes, and" like products. vMorespeciiically, the invention relatesto` improvements infthe art, referredto in my pre- 'viously filed `applicationsy Serial No. 743,624, filedlune 23, 1958,' and SerialNo; 756,405, iiled August 2.1, 1958. I It is aprimary object of the presentinvention to provide an improvedpapermakers felt constructed of any oftheconventionally used grades ofwool, cotton, or other natural or synthetic fibres or combinationsthereof; so fabricated as to provide a papermakers felt, which at thesame time possesses optimum lateral balance and resstance tolongitudinal curl, and is of high bulk characteristics. l j l Anotherobject ofthe invention is to provide a felt as aforesaid which presentsa smooth working surface of improved p ulp supporting andv cushioning'characteristics. Another object is Vto provide a felt as aforesaid whichisv eiiicient as` a `drainage iilter in its intended use. Still anotherobject is to provide an improved felt as aforesaidv whichis ofldesirable strength in the direction ofthe feltfloadandwhicli' alsoinherently possesses improvedf dimensional stability characteristics. fffOthei' A'objects'and advantages of the invention will appear-,fronrthespecification hereinafter, and the accompanying drawings wherein: A Fig.l is a diagrammatic perspective View of one form of plied yarnlsuch' asmaybe employed in construction of afelt of the` present invention; Fig.2 isa planiview (at reduced scale) of a laterally distorted swatch` offabric, illustrating the braid pattern employed in thernanufacture ofthe felt, the yarnsbeing shown `as variouslyfcolored to facilitatereading the drawing; f l Fig. 3 is a plan view corresponding to Fig. 2but of a swatch of the fabrication as it actually appears subsequent toinitial braiding thereof; and Fig. 4 is a diagrammatic fragmentary'sectional view taken along line IVl-IV of Fig. 2.4

z' In the papermakerswetfelt art it is a prime object to provide a'fabric structure which is of high bulk characteristics yetlongitudinally strong, comprising an eiiicient water-'drainage or iiltermembrane. For such purposes the lwool and/ or other fibres used must beso integrated as ytopr'esent to the pulp being treated a uniformlys'moothandfle'vel yet resilient surface. The present in- Ventionprovides the vabove stated objects through use of a novel fabrication ofyarns whereby the individual fibres subsequentv to the yarn interlockingoperation remain free to move relative to one another during the fabricrn systems, and may be either singles or plied" yarns.

In fabricating a felt of the present invention either a singles yarn oraconventional plied yarn may be employed. Or, as still anotheralternative, as a separate operation, Va plurality of singles .yarnsmade with a singles twist such as the pair of yarns 10-1'2 shown in Fig.l may be' plied as by means of a neutralizing Z twist. Hence, theresultant plied yarnv designated generally at 14 comprises intertwinedsingles yarns, the individual iibres of which are as near as possibleuntwisted. V.By way of a specic example, the card roping may beinitiallydrafted and S twisted at the rate for example of 4.0 t.p.i.(twists per inch), depending upon the fibre lengths and other variables.The two singles yarns so produced may then be relatively entwined bymeans of a neutralizing Z twist in such manner as to provide a pliedyarn for example of 4.5 t.p.i. Approximately this ratio of singles andplied yarn twists will rev stock 14 as explained hereinabove.

sult in production'of a plied yarn as indicated at 14 in the drawingwherein the individual libres are only very slightly twisted (in `onedirection or the other) or are substantially untwisted aboutv their ownaxes, while gently winding spirally about the neutral axis of the yarn.

-In the alternative, the card roping may be initially formed intosingles yar-n stock by means of a Z twist operation, and the singlesyarns may thereupon be S twisted into plied yarn form, to provide theplied yarn In either case the yarn stock may be described as comprisingtwo groups of untwisted fibres gently rolling around vone another. Dueto the fact that the singles yarns are relatively entwined the overallstructure of the plied yarn 14 has adequate strength to withstand thesubsequent braiding operation, in spite yof thefact that the individualfibre are substantially untwisted.

Asr the second step in the manufacture of the felt of the presentinvention, pluralities of the yarns 14 are intertwined as shown in Fig.2.` The construction is illustrated herein as when being laterallystretched out of its natural se condition, to facilitate understandingthe nature of the yarn interweaving system. When the structure isrelaxed its longitudinal resiliency causes it to return to its normalcondition as shown in Fig. 3 and it will be noted that the yarns14 areinterlinked and nested together in a manner quite unique in the wet feltart. Each plied yarn member of the system runs generally longitudinallyof thebelt into which the fabric is made, although it follows a slightlyzig-zag course. To facilitate reading the Vdrawing some of the yarns aredarkly colored as indicated at 16 in Figs. 2, 3. It will be seen thatalong each leg of the zig-zag course each yarn passes rst over twoadjacent yarns and then reverses course and passes under the same twoyarns. yIt then reverses course again and passesover the same two yarns,but then continues on the same course and passes under two more yarns.It then reverses course and passes over the two last mentioned yarns,whereupon it reverses again and passes under the two last mentionedyarns; and so on throughout the length of the fabrication. In my priorapplication Serial No.` 743,624 referred to hereinabove, each yarnpasses either over or under all of the adjacent yarns throughout eachleg of its zig-zag course, and in application Serial No. 756,405 eachyarn passes first over two yarns and'then u nder two yarns, and thenreverses course and passes under two yarns and then over, and so on.Thus the constructions are substantially different.

Subsequent to braiding, the fabric is submitted to any suit-ableshrinking and fulling orlmillingf operations;-

and thus the `fabric isV shrunk and fulled as into the 3 formillustrated by Figs. 3-4. As shown in Fig. 3, the yarns 14 aresubstantially straightened out in plan view to their conditions ofmaximum eiciency with respect to resistance to tension loads on thefelt. It will of course be understood that the fabric of the inventionmay be constructed by any suitable type machine.

Whereas, the yarns 14, due to their relatively entwined positions in theinterlock pattern acquire optimum felt tension resistancecharacteristics, the locally soft nature of the yarn stock permit themto easily deform and bulk out and respond in improved manner to thefulling treatment because the individual fibres thereof are of improvedmobility. Hence, in the resulting lfelt fabrication the fibres provide amat of superior surface smoothness and cushioning characteristics. Atthe same time the double thickness and laterally unrestrained nature ofthe interlock pattern permits the fabric to breathe and to operate withmaximum efficiency in accord with the phenomenon of capillarity and inresponse to the pumping action within the felt when passing throughcompression rolls; thereby improving its water removing abilities. Forthe same reason the fabric is of improved inherent selfcleaningcharacteristics and is more responsive to conventional cleaning devicesthan are felts of other construction. Thus, each fibre of thefabrication is disposed to act more eiciently in its assigned task.

By virtue of the more efficient bulking of the fibres in the felt of theinvention, it is of superior surface or finish characteristics. It is afeature of this invention that in the finished felt belt the individualyarns and fibres are disposed at angles only slightly oblique to thedirection of Ibelt travel (Fig. 3); thereby providing a felt ofincreased total load pulling power for the same felt weight, andavoiding head-on impacts of yarn rises or floats against stationaryequipment such as suction boxes, cleaning shoes, etc.

' It is a particular feature of the present invention that by virtue ofthe braid pattern of the yarns a belt (such as a papermakers felt) madefrom this fabric is laterally balanced and does not tend to curl up inthe direction of its yarns. Hence, the felt is inherently balanced andtends to ride true on the rollers of the paper making machine. At thesame time the fabric yarns retain their optimum bulk characteristics, asexplained hereinabove. Thus, it will of course be appreciated that theinvention is not limited to the precise construction illustrated hereinnor to the specific wet felt usage described hereinabove, and that theconstruction may be modified such as 4for example by interlacing eachyarn any other desired number of times with adjacent yarns along eachshort general course before reversing course into a long general course,without departing `from the spirit of the invention or the scope of theappended claims.

I claim:

1. A new papermakers felt belt for supporting and draining paper makingmaterial, said belt comprising a felt-like fabric structure having onlysubstantially untwisted yarns running generally parallel and lengthwiseof the belt with adjacent yarns interlocked by means of a braidingpattern disposing each yarn member to follow a slightly zig-zag courselengthwise of the belt, each yarn member passing lalong each leg of thezig-zag course first over two adjacent yarns of adjacent courses, andthen reversing to pass under the same two yarns; again reversing courseand passing over the same two yarns and then passing under pairedadjacent yarns while continuing on the same course, whereupon it againreverses course and repeats the aforesaid pattern, the individual fibresof said yarns being spirally wound but substantially untwisted abouttheir own axes, said yarns each comprising card roping twisted onlyslightly into twisted yarn form, said fabric being fulled.

2. A new papermakers felt belt for supporting and draining paper makingvmaterial, said belt comprising a felt-like fabric formed` solely ofrelatively soft twisted yarns running lengthwise thereof in side-by-siderelation and interlocked by means of a braiding pattern disposing eachyarn member to follow a slightly zig-zag course lengthwise of the belt,each yarn member passing along each leg of the zig-zag course first overtwo adjacent yarns of adjacent courses, and then reversing to pass underthe same two yarns; again reversing course and passing over the same twoyarns and then passing under paired adjacent yarns while continuing onthe same course, whereupon it again reverses course and repeats theaforesaid pattern, the individual fibres of said yarns beingsubstantially untwisted about their own axes, said fabric being fulled.

3. A new papermakers felt belt for supporting and draining paper makingmaterial, said belt comprising a felt-like structure having onlysubstantially untwisted plied warp yarns running generally parallel andlengthwise thereof with adjacent yarns interlocked by means of abraiding pattern disposing each yarn member to follow a slightly zig-zagcourse lengthwise of the belt, each yarn member passing along each legof the zig-Zag course first over two adjacent yarns of adjacent courses,and then reversing to pass under the same two yarns; again reversingcourse and passing over the same two lyarns and then passing underpaired adjacent yarns while continuing on the same course, whereupon itagain reverses course and repeats the aforesaid pattern, the individualfibres of said yarns being spirally wound but substantially untwistedabout their own axes, said plied yarns each comprising a pair of singlesyarns each comprising card roping twisted into conventional S twistedyarn form and Z twisted together in opposite direction into plied yarnform, said interlocked yarns being fulled.

4. A new papermakers fabric belt for supporting and draining papermaking material, said belt comprising a felt-like structure havingrelatively soft twisted warp plied yarns running lengthwise thereof inside-by-side relation and interlocked by means of a braiding patterndisposing each yarn member to follow a slightly zig-zag courselengthwise of the belt, each yarn member passing along each leg of thezig-zag course first over two adjacent yarns of adjacent courses, andthen reversing to pass under the same two yarns; again reversing courseland passing over the same two yarns and under paired adjacent yarnswhile continuing on the same course, whereupon it -again reverses courseand repeats the aforesaid pattern, the individual libres of said yarnsbeing substantially untwisted about their own axes, said yarns eachcomprising a pair of singles yarns twisted together into plied yarnform, said fabric being fulled.

5. A new papermakers felt fabric for supporting and draining papermaking material, said fabric comprising a structure of relativelysoft-twisted plied yarns running lengthwise thereof in side-by-siderelation and interlocked by means of a braiding pattern disposing eachyarn member to follow a slightly zig-zag course lengthwise of thefabric, each yarn member passing along each leg of Ithe zig-zag coursefirst over adjacent yarns of adjacent oourses, and then reversing topass under the same two yarns; again reversing course and passing overthe same two yarns and under paired adjacent yarns while continuing onthe same course, whereupon it again reverses course and repeats theaforesaid patern, said yarns having their individual fibressubstantially untwisted about their own axes and each comprising a pairof singles yarns S twisted together into plied yarn form, each of saidsingle yarns comprising card roping Z twisted in opposite direction intosingles yarn form, said fabric being fulled.

6. A papermakers felt for supporting and draining paper making material,said felt comprising a fabric structure having plied yarns runninglengthwise thereof in sideaby-side relation and interlocked by means ofa braiding pattern disposing each yarn member to follow a slightlyzig-zag course` lengthwise of the belt, each yarn member passing alongeach leg of the zig-zag course rst over adjacent yarns of adjacentcourses, and then reversing to pass under the same two yarns; againreversing course and passing over the same two yarns and under pairedadjacent yarns while continuing on Ithe same course, whereupon it againreverses course and repeats the aforesaid patern, said yarns eachoomprising a plurality of singles yarns twisted together cinto pliedyarn form, each of said singles yarns comprising card roping twistedinto yarn form, said fabric being fulled.

7. A new papermakers felt for supporting and draining paper makingmaterial, comprising a fabric structure having only warp yarns, saidwarp yarns running lengthwise of the fabric and in side-by-siderelation, each warp yarn being intenlocked alternately with yarnsadjacent thereto by means of a braiding pattern disposing each yarnmember to follow a slightly zig-zag course lengthwise of the belt, eachyam member passing along References Cited in the le of this patentUNITED STATES PATENTS 897,551 Lundgren Sept. 1, 1908 1,497,068Collingbofurne June 10, 1924 2,423,828 Chagnon July 15, 1947 OTHERREFERENCES Eifect of Ply Twist on Single Twist from Textile World,February 21, 1931, page 38. Copy in Class 57- 139, Div. 21.

